Magnetic field formation device, power supplying device, power receiving device, power receiving/supplying device, portable device, coil device, and magnetic field formation method

ABSTRACT

A variable magnetic field in which a power-supplying coil and a power supplying resonator exist is generated only by the power-supplying coil. Power-supplying coils and each of which generates a variable magnetic field due to the supply of a variable current via a first current path on one coil end a side and a second current path on the other coil end side; resonance capacitors which are provided on the first current path and the second current path; and a power-supplying coil short-circuit mechanism which is able to cause at least one of the power-supplying coils and to function as a power supplying resonator by allowing the end portions and of the first current path and the second current path to short-circuit with each other are provided.

TECHNICAL FIELD

The present invention relate to a magnetic field formation deviceforming a magnetic field at a predetermined region, a power-supplyingdevice, a power-receiving device, a power receiving/supplying device, amobile device, a coil device, and a magnetic field formation method.

BACKGROUND

A structure of wireless power transmission from a power feeding coil toa power-receiving coil by electromagnetic induction or magnetic fieldresonance has been proposed (e.g., Patent Literature 1 and PatentLiterature 2).

CITATION LIST Patent Literature

[Patent Literature 1] Japanese Unexamined Patent Publication No.2015-144508

[Patent Literature 2] Japanese Unexamined Patent Publication No.2013-240260

SUMMARY OF INVENTION Technical Problem

In regard to the above, the roles and functions of the power feedingcoil and the power-receiving coil have been fixed, and there has been nostructures focusing on the roles and functions of the coils.

An object of the present invention is to provide a magnetic fieldformation device, a power-supplying device, a power-receiving device, apower receiving/supplying device, a mobile device, a coil device, and amagnetic field formation method, which form a magnetic field with focuson the roles and functions of the coils.

Solution to Problem

The present invention relates to a magnetic field formation device whichincludes: power-supplying coils each of which generates a variablemagnetic field as a variable current is supplied to each of thepower-supplying coils via a first current path on one coil end side anda second current path on the other coil end side; a resonance capacitorwhich is provided on at least one of the first current path and thesecond current path; and a power-supplying coil short-circuit mechanismwhich is capable of causing at least one of the power-supplying coils tofunction as a power supplying resonator by short-circuiting end portionsof the first current path and the second current path.

According to the arrangement above, when the end portions of the firstcurrent path and the second current path of at least one of thepower-supplying coils are short-circuited by the power-supplying coilshort-circuit mechanism, this power-supplying coil functions as a powersupplying resonator which resonates with a variable magnetic fieldgenerated by the other power-supplying coil to which a variable currentis supplied. In this way, a variable magnetic field in which thepower-supplying coil and the power supplying resonator exist isgenerated only by the power-supplying coils.

The magnetic field formation device of the present invention maygenerate a variable magnetic field at a predetermined region, all of thepower-supplying coils may be disposed so that coil surfaces oppose thepredetermined region, and at least one of the power-supplying coils maybe disposed to have a coil surface direction which intersects with coilsurface directions of the other power-supplying coils. The magneticfield formation device of the present invention may generate a variablemagnetic field at a predetermined region, all of the power-supplyingcoils maybe disposed so that coil surfaces oppose the predeterminedregion, and at least one of the power-supplying coils may be disposed tohave a coil surface direction which is parallel to coil surfacedirections of the other power-supplying coils.

According to the arrangements above, a variable magnetic field in whichthe power-supplying coil and the power supplying resonator exist isgenerated at the predetermined region only by the power-supplying coils.According to the arrangements above, furthermore, a variable magneticfield with high magnetic field strength or low magnetic field strengthcan be formed at a part of the predetermined region by the variablemagnetic field of the power-supplying coil and the variable magneticfield of the power-supplying coil functioning as a power supplyingresonator, based on the positional relation between the power-supplyingcoils. This is achieved by adjusting the angles, locations, etc. of thecoil surfaces of the power-supplying coils.

The magnetic field formation device of the present invention may furtherinclude a current output controller which is configured to output avariable current to one of output targets which are at least one of andnot all of the power-supplying coils and to be capable of switching theoutput target to which the variable current is output.

According to this arrangement, it is possible to change the distributionof the magnetic field strength of a variable magnetic field by sending amagnetic field from each power-supplying coil to the power-supplyingcoil functioning as the power supplying resonator at a different angle.Furthermore, as the power supplying resonator (power-supplying coil)resonates on account of the variable magnetic field of each of thepower-supplying coils, the magnetic field strength of the variablemagnetic field at the predetermined region is enhanced.

The magnetic field formation device of the present invention may bearranged such that the current output controller executes a stop processof not outputting the variable current to any of the power-supplyingcoils, with a predetermined combination of a timing and a duration.

With this arrangement, it is possible to easily generate a variablemagnetic field with predetermined magnetic field strength inconsideration of heat generation and power consumption, by adjusting thetiming and duration of the stop process.

The present invention relates to a power-supplying device including oneof the above-described magnetic field formation devices.

The present invention relates to a power-receiving device including apower-receiving mechanism which is configured to receive power by avariable magnetic field generated at a predetermined region by anyone ofthe above-described magnetic field formation devices.

The power-receiving device of the present invention may include: apower-receiving mechanism configured to receive power by the variablemagnetic field; and a high-capacitance capacitor which has a capacity ofbeing charged by a current received by the power-receiving mechanism anddischarging at least at a minimum operating voltage of an electric parton a subsequent stage while an output target of the variable current bythe current output controller is being switched.

According to the arrangement above, even when an induced current cannotbe easily obtained from the power-receiving mechanism on account of theswitching of the output target of the variable current, the electricpart is stably driven because the high-capacitance capacitor performsthe discharge at least at the minimum operating voltage of the electricpart.

The high-capacitance capacitor of the power-receiving device of thepresent invention may have a capacity of discharging at least at theminimum operating voltage of the electric part on the subsequent stageduring a stop process in which the current output controller does notsupply the variable current to any of the power-supplying coil.

According to this arrangement, in addition to the period during whichthe switching of the output target of the variable current is beingperformed by the current output controller, even when an induced currentcannot be obtained from the power-receiving mechanism due to the stopprocess for the power-supplying coil and the power supplying resonator,the electric part is stably driven as the high-capacitance capacitorperforms the discharge at least at the minimum operating voltage of theelectric part.

The present invention relates to a power receiving/supplying deviceincluding: a power-supplying device including any one of theabove-described magnetic field formation devices; and a power-receivingdevice including a power-receiving mechanism which is configured toreceive power by the variable magnetic field generated by thepower-supplying device.

The present invention relates to a mobile device including apower-receiving mechanism which is configured to receive power by avariable magnetic field generated at a predetermined region by any oneof the above-described magnetic field formation devices.

The present invention relates to a coil device including: a coil; avariable current supplying mechanism configured to supply a variablecurrent to the coil via a first current path on one coil end side and asecond current path on the other coil end side; a resonance capacitorwhich is provided on at least one of the first current path and thesecond current path, in a connection state which is a least one ofconnection in series with the coil and connection parallel to the coil;and a coil short-circuit mechanism which is capable of forming a powersupplying resonator by short-circuiting end portions of the firstcurrent path and the second current path.

According to this arrangement, the coil is switchable between a coilgenerating a variable magnetic field and a power supplying resonatorresonating with a variable magnetic field.

The present invention relates to a magnetic field formation methodincluding the steps of: generating a variable magnetic field bysupplying a variable current via a first current path on one coil endside and a second current path on the other coil end side; and switchingat least one of power-supplying coils to a power supplying resonator byshort-circuiting end portions of the first current path and the secondcurrent path, a resonance capacitor being provided on at least one ofthe first current path and the second current path of thepower-supplying coils.

According to the arrangement above, when the end portions of the firstcurrent path and the second current path of at least one of thepower-supplying coils are short-circuited, this power-supplying coilfunctions as a power supplying resonator which resonates with a variablemagnetic field generated by the other power-supplying coil to which avariable current is supplied. In this way, a variable magnetic field inwhich the power-supplying coil and the power supplying resonator existis generated only by the power-supplying coils.

Advantageous Effects

According to the present invention, a variable magnetic field in whichthe power-supplying coil and the power supplying resonator exist isgenerated only by the power-supplying coils.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 2A illustrates a connection relation between a power-supplying coiland a resonance capacitor.

FIG. 2B illustrates a connection relation between a power-supplying coiland a resonance capacitor.

FIG. 2C illustrates a connection relation between a power-supplying coiland a resonance capacitor.

FIG. 2D illustrates a connection relation between a power-supplying coiland a resonance capacitor.

FIG. 2E illustrates a connection relation between a power-supplying coiland a resonance capacitor.

FIG. 2F illustrates a connection relation between a power-supplying coiland a resonance capacitor.

FIG. 2G illustrates a connection relation between a power-supplying coiland a resonance capacitor.

FIG. 2H illustrates a connection relation between a power-supplying coiland a resonance capacitor.

FIG. 3 is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 4A is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 4B is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 5 is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 6 is a schematic explanatory diagram of a magnetic field formationdevice in a plan view.

FIG. 7 is a schematic explanatory diagram of a magnetic field formationdevice in a plan view.

FIG. 8 is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 9 is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 10 is a schematic explanatory diagram of a magnetic field formationdevice in a plan view.

FIG. 11 is a block diagram of a magnetic field formation device.

FIG. 12 illustrates operations of a power-supplying coil short-circuitmechanism.

FIG. 13 is a block diagram of a magnetic field formation device.

FIG. 14 is an explanatory diagram of operations of a current pathswitcher.

FIG. 15 is a block diagram of a power receiving/supplying device.

FIG. 16 is a block diagram of a driving device.

FIG. 17 is a block diagram of a driving device.

FIG. 18 is a block diagram of a driving device.

DESCRIPTION OF EMBODIMENTS

The following will describe an embodiment of the present invention withreference to drawings. (Magnetic Field Formation Device: Overview)

As shown in FIG. 1, a magnetic field formation device 101 includes:power-supplying coils 111 and 112 each of which generates a variablemagnetic field due to the supply of a variable current via a firstcurrent path 141 on one coil end 141 a side and a second current path142 on the other coil end 142 a side; resonance capacitors 151 and 151which are provided on the first current path 141 and the second currentpath 142; and a power-supplying coil short-circuit mechanism 1313 whichis able to cause at least one of the power-supplying coils 111 and 112to function as a power supplying resonator by allowing the end portions141 a and 142 a of the first current path 141 and the second currentpath 142 to short-circuit with each other.

Each resonance capacitor 151 is provided on the first current path 141or the second current path 142 to be in series with or parallel to oneof the power-supplying coils 111 and 112. Specific examples are shown inFIG. 2A to FIG. 2H.

FIG. 2A shows a state in which a resonance capacitor 151 is connected inseries at a part of the first current path 141, which is between the endportion 141 a of the first current path 141 and the coil end of thepower-supplying coil 111. FIG. 2B shows a state in which two resonancecapacitors 151 are connected in series on the first current path 141.FIG. 2C shows a state in which resonance capacitors 151 are connected inseries on the first current path 141 and the second current path 142,respectively.

FIG. 2D shows a state in which two resonance capacitors 151 provided ina parallel manner are connected in series on the first current path 141.FIG. 2E shows a state in which two resonance capacitors 151 provided ina parallel manner are connected in series on the first current path 141whereas a resonance capacitor 151 is connected in series on the secondcurrent path 142. FIG. 2F shows a state in which two resonancecapacitors 151 provided in a parallel manner are connected in series onthe first current path 141 whereas two resonance capacitors 151 providedin a parallel manner are connected in series on the second current path142.

FIG. 2G shows a state in which a resonance capacitor 151 is connected tothe first current path 141 and the second current path 142 to beparallel to the power-supplying coil 111. FIG. 2H shows a state in whicha resonance capacitor 151 is connected to the first current path 141 andthe second current path 142 to be parallel to the power-supplying coil111, and a resonance capacitor 151 is connected in series on the firstcurrent path 141. The connection states shown in FIG. 2A to FIG. 2H areexamples, and the number, the series connection, the parallelconnection, and the locations of the resonance capacitors 151 may besuitably selected and combined.

As shown in FIG. 1, the power-supplying coil short-circuit mechanism1313 is provided in an oscillation controller 131 together with anoscillator 1312. The oscillation controller 131 will be detailed later.With this arrangement, the magnetic field formation device 101 realizesa magnetic field formation method of switching at least one of thepower-supplying coils 111 and 112 generating a variable magnetic fieldwith the supply of a variable current to a power supplying resonator byshort-circuiting the end portions 141 a and 142 a of the first currentpath 141 and the second current path 142 with each other.

In the magnetic field formation device 101 structured as describedabove, when the end portions 141 a and 142 a of the first current path141 and the second current path 142 of at least one of thepower-supplying coils 111 and 112 are short-circuited by thepower-supplying coil short-circuit mechanism 1313, this power-supplyingcoil 111 (112) functions as a power supplying resonator which resonateswith a variable magnetic field generated by the other power-supplyingcoil 112 (111) to which a variable current is supplied. In this way, avariable magnetic field in which the power-supplying coil 111 (112) andthe power supplying resonator 112 (111) exist is generated only by thepower-supplying coils 111 and 112.

The magnetic field formation device 101 may be formed by at lest onecoil device which is configured to switch the power-supplying coil 112(111) between a coil for electromagnetic induction and a coil formagnetic field resonance by whether to short-circuit the end portions141 a and 142 a of the first and second current paths 141 and 142 by thecoil short-circuit mechanism 1313.

To specifically describe the coil device, the coil device includes acoil, a resonance capacitor which is provided on at least one of thefirst current path on one coil end side and the second current path onthe other coil end side of the coil, and a coil short-circuit mechanismwhich is capable of causing the coil to function as a resonator bycausing the end portions of the first current path and the secondcurrent path of the coil to be short-circuited. This coil may be apower-supplying coil or a power-receiving coil. According to thisarrangement, the coil device is able to switch the coil between a coilfor electromagnetic induction and a coil for magnetic field resonance bywhether to short-circuit the end portions of the first and secondcurrent paths by the coil short-circuit mechanism.

Furthermore, the coil device may include a current output unit whichsupplies a variable current via the first current path and the secondcurrent path. According to this arrangement, the coil is switchablebetween a power-supplying coil for electromagnetic induction and apower-supplying resonance coil for magnetic field resonance by whetherto short-circuit the end portions of the first and second current pathsby the coil short-circuit mechanism, even in a state i which theoperation f the current output unit outputting a variable current ismaintained, i.e., without stopping an output from the current outputunit.

All of the power-supplying coils 111 and 112 are provided so that coilsurfaces 111 a and 112 a oppose the predetermined region A, and at leastone of the power-supplying coils 111 and 112 is provided to have a coilsurface direction intersecting with the coil surface direction of theother one of the power-supplying coils 111 and 112. The coil surfacedirection is a direction in parallel to a coil surface.

Alternatively, as shown in FIG. 3, at least one of the power-supplyingcoils 111 and 112 may be provided to have a coil surface directionparallel to the coil surface direction of the other one of thepower-supplying coils 111 and 112. In this case, the power-supplyingcoils 111 and 112 maybe arranged so that the coil surfaces 111 a and 112a having the coil surface directions parallel to each other sandwich atleast a part of the predetermined region A. Furthermore, in the caseabove, the power-supplying coils 111 and 112 may be disposed to at leastpartially overlap each other when one of the coil surfaces 111 a and 112a having the coil surface directions parallel to each other is projectedonto the other coil surface in the direction along the coil axis.

Alternatively, the power-supplying coils 111 and 112 may be disposed sothat the coil surface 111 a or 112 a of at least one of thepower-supplying coils 111 and 112 and the coil surface 111 a or 112 a ofthe other one of the power-supplying coils 111 and 112 are not on thesame plane.

In the magnetic field formation device 101 structured as above, avariable magnetic field with high magnetic field strength or lowmagnetic field strength can be formed at a part of the predeterminedregion A by the variable magnetic field of the power-supplying coil 111(112) and the variable magnetic field of the power-supplying coil 112(111) functioning as a power supplying resonator, based on thepositional relation between the power-supplying coils 111 and 112. Thisis achieved by adjusting the angles, locations, etc. of the coilsurfaces 111 a and 112 a of the power-supplying coils 111 and 112. Inthis way, a magnetic field which is partially a variable magnetic fieldwith high or low magnetic field strength can be formed at thepredetermined region A.

Furthermore, in the magnetic field formation device 101, by thepower-supplying coil 111 (112) functioning as a power supplyingresonator and the other power-supplying coil 112 (111), a magnetic fieldarea which enables power transmission by magnetic field resonance and amagnetic field area which enables power transmission by electromagneticinduction can be provided in the predetermined region. In other words,in the magnetic field formation device 101, because the distance inwhich the magnetic field resonance is possible is longer than thedistance in which the electromagnetic induction is possible, a magneticfield area in which power transmission is mainly conducted by theelectromagnetic induction in short distances from the power-supplyingcoil 111 (112) and a magnetic field area in which power transmission isconducted mainly by the magnetic field resonance in long distances canbe provided in the predetermined region. On this account, the magneticfield formation device 101 is suitable for power transmission in alarge-sized predetermined region.

The “variable magnetic field” indicates one of (1) a magnetic field in astate in which the direction of the magnetic lines of force alternatelychanges between the forward direction and the reverse direction, (2) amagnetic field in a state in which the magnetic field strength changeswhile the direction of the magnetic lines of force is the forwarddirection, (3) a magnetic field in a state in which the magnetic fieldstrength changes while the direction of the magnetic lines of force isthe reverse direction, and (4) a magnetic field in a state in which twoor more of the states (1) to (3) are combined.

The “predetermined region A” may be of any size or shape. Thepredetermined region A is a reverse frustum in shape, in which the lowerface is smaller than the upper face. The reverse frustum shape may be areverse circular frustum shape, a reverse square frustum shape, or anN-sided frustum shape. While in the present embodiment the predeterminedregion A is reverse frustum in shape, the disclosure is not limited tothis arrangement. In other words, as shown in FIG. 4A, the inclinationangle of at least one side face may be different from the inclinationangles of the remaining side faces in the predetermined region A, or thepredetermined region A may be a frustum in which the lower face islarger in diameter than the upper face as shown in FIG. 4B. Thepredetermined region A may be sized and shaped to correspond to anobject provided in the variable magnetic field, or may be sized andshaped to correspond to a receiving space such as a container, a housingbox, a room, etc. in which the object is housed. The “predeterminedregion A: may be a hexahedron such as a rectangular parallelepiped body,a cube, or a triangular prism.

An example of the “object” is a driving device including apower-receiving device to which power is supplied by a variable magneticfield. The driving device encompasses all types of devices driven byelectric power. Examples are a mobile device, a home electric appliance,and an automobile.

While in the present embodiment the magnetic field formation device 101includes only the power-supplying coils 111 and 112, the magnetic fieldformation device 101 may include at least one power supplying resonator.The “power supplying resonator” is of a spiral type, a solenoid type, ora loop type, for example, and is a coil in which the ends of the coilare directly connected (short-circuited) to each other or indirectlyconnected (short-circuited) to each other by a GND or the like. When aninduced current is supplied, the power supplying resonator generates avariable magnetic field at the predetermined region A opposing the coilsurface and generates a variable magnetic field at a region opposite tothe predetermined region A over the power supplying resonator.

While in the present embodiment one oscillation controller 131 isprovided for plural power-supplying coils 111 and 112, the disclosure isnot limited to this arrangement and an oscillation controller 131 may beprovided for each of power-supplying coils 111 and 112. In other words,the magnetic field formation device 101 may be formed by combining acoil device including a coil (power-supplying coil 111), a variablecurrent supply mechanism (oscillator 1312) configured to supply avariable current to the coil, and a coil short-circuit mechanism(power-supplying coil short-circuit mechanism 1313) capable of causingthe end portions 141 a and 142 a of the first current path 141 and thesecond current path 142 to be short-circuited. According to thisarrangement, because the coil of each coil device is switchable betweena coil generating a variable magnetic field and a power supplyingresonator resonating with a variable magnetic field, the control formagnetic field formation may be easily done.

(Magnetic Field Formation Device: Power-Supplying Coil)

The “power-supplying coils 111 and 112” are of a spiral type, a solenoidtype, or a loop type, for example, and are coils which generate aninduction current at a power-supplying coil 111 or 112 which functionsas a power supplying resonator on account of an externally-suppliedvariable current. The “variable current” indicates one of (1) a currentwhich alternately varies to the positive side and the negative side over0 ampere, (2) a current which varies on the positive side, (3) a currentwhich varies on the negative side, and (4) a current in a state in whichtwo or more of the states (1) to (3) are combined.

All of the power-supplying coils 111 and 112 are provided so that coilsurfaces 111 a and 112 a oppose the predetermined region, and at leastone of the power-supplying coils 111 and 112 is provided to have a coilsurface direction intersecting with the coil surface direction of theother one of the power-supplying coils 111 and 112. For example in caseof the magnetic field formation device 101, 101A including thepredetermined region A as shown in FIG. 1 and FIG. 4A, thepower-supplying coils 111 and 112 are disposed along the side faces ofthe predetermined region A and hence the coil surface directionsintersect with each other at a location below the predetermined regionA. In case of the magnetic field formation device 101B including thepredetermined region A as shown in FIG. 4B, the power-supplying coils111 and 112 are disposed along the side faces of the predeterminedregion A and hence the coil surface directions intersect with each otherat a location above the predetermined region A.

While in FIG. 1, FIG. 4A, and FIG. 4B two power-supplying coils 111 and112 are provided for convenience of explanation, the number of thepower-supplying coils is not limited to this. The number of thepower-supplying coils may be variously set on condition that the numberis two or more. For example, as shown in FIG. 5, three power-supplyingcoils 111, 112, and 115 are provided, and a coil surface 115 a of thepower-supplying coil 115 is disposed to oppose the bottom surface of thepredetermined region A.

Alternatively, for example, as shown in FIG. 6, when viewed from a pointabove the predetermined region A, three power-supplying coils 111, 112,and 113 may be provided along the respective sides of an equilateraltriangle which is centered at the predetermined region A. In this case,the state of the end face cut along the X-X line in FIG. 6 correspondsto the positional relation between the power-supplying coils 111, 112,and 115 shown in FIG. 5.

Alternatively, for example, as shown in FIG. 7, when viewed from a pointabove the predetermined region A, four power-supplying coils 111, 112,113, and 114 may be provided along the respective sides of a squarewhich is centered at the predetermined region A. In this case, the stateof the end face cut along the X-X line in FIG. 7 corresponds to thepositional relation between the power-supplying coils 111, 112, and 115shown in FIG. 5.

As shown in FIG. 8, the coil surfaces of the power-supplying coils 111and 112 provided to sandwich the predetermined region A have sizes andshapes corresponding to those of the side faces of the predeterminedregion A. For example, the coil surfaces 111 a and 112 a of thepower-supplying coils 111 and 112 may be formed to be trapezoidal tocorrespond to the predetermined region A having a reverse frustum shape,or to be elliptical (power-supplying coil 111A). Each of the coilsurfaces of the power-supplying coils 111 and 112 may be, for example,circular, triangular, quadrangular, or polygonal in shape to correspondto the size of the predetermined region A. The shapes of the coilsurfaces 111 a and 112 a of the power-supplying coils 111 and 112 may bedifferent from each other. The coil surfaces 111 a and 112 a of thepower-supplying coils 111 and 112 may be formed to correspond to aprojected shape of a side face of the predetermined region A, or may beformed in accordance with factors such as the disposition of the otherpower-supplying coils 111, 112, and 115.

Each of the power-supplying coils 111 and 112 may be formed of pluralpower supplying sub coils. For example, in the power-supplying coil 111,a coil surface 111 a which is trapezoidal on the whole may be formed bygathering power supplying sub coils 1111 which are identical ordifferent in size. Alternatively, in the power-supplying coil 111, acoil surface 111 a which is trapezoidal on the whole may be formed bygathering power supplying sub coils 1111 and power supplying sub coils1112 which are different in shape from the power supplying sub coils1111 and each of which is trapezoidal, for example.

The power-supplying coils 111 and 112 may be disposed so that the outerperipheries thereof partially overlap each other. With this arrangement,the magnetic field strength is easily uniformized by causing the outerperipheries of the power-supplying coils 111 and 112 with low magneticfield strength to overlap each other.

A coil surface 115 a of the power-supplying coil 115 provided below thepredetermined region A is sized and shaped to correspond to the size andshape of the bottom of the predetermined region A. For example, the coilsurface 115 a of the power-supplying coil 115 may be circular in shapeto correspond to the size of the predetermined region A, or may haveanother shape. To be more specific, the coil surface 115 a may betriangular as in a power-supplying coil 115A, the coil surface 115 a maybe quadrangular as in a power-supplying coil 115B, or the coil surface115 a may have another shape such as polygonal or elliptical. The shapeof the coil surface 115 a of the power-supplying coil 115 may correspondto the shape of the bottom of the predetermined region A, or may bedetermined in accordance with factors such as the disposition of theother power-supplying coils 111 and 112.

The number of the power-supplying coils 115 is one or more. When thereare plural power-supplying coils 115, each of the power-supplying coils115 may have a coil surface with a desired shape, as power supplying subcoils 1151 which are identical or different in size are gathered.Alternatively, a power-supplying coil 115 may be formed of an annularpower supplying sub coil 1152 corresponding to the coil surface shapeand power supplying sub coils 1151 provided on the inner circumferentialside of the power supplying sub coil 1152. When a power-supplying coil115 is formed by plural power supplying sub coils 1151 (1152), it ispossible to finely adjust the magnetic field strength of a variablemagnetic field at around the bottom portion of the predetermined regionA, by each power supplying sub coil 1151 (1152).

As shown in FIG. 9 and FIG. 10, the magnetic field formation device 101may be arranged such that plural, e.g., three power-supplying coils 111,112, and 113 are disposed to form a flat plate. In other words, thepower-supplying coils 111, 112, and 113 may be disposed so that the coilsurfaces 111 a, 112 a, and 113 a of the power-supplying coils 111, 112,and 113 are on the same plane. In this case, the size and shape of thepredetermined region A in the planar direction can be arbitrarily set byincreasing the number of the power-supplying coils 111, 112, and 113provided. The disposition direction may be a horizontal direction, avertical direction, or a direction inclined with respect to the verticaldirection or the horizontal direction.

(Magnetic Field Formation Device: Oscillation Controller)

As shown in FIG. 11, the magnetic field formation device 101 structuredas described above includes the oscillation controller 131 (which is anexample of a current output controller) connectable to an external powersource PS. While a magnetic field formation device 101 including threepower-supplying coils 111, 112, and 113 will be described below, thedisclosure is not limited to this arrangement.

The oscillation controller 131 includes: a power-supplying coilshort-circuit mechanism which causes each of the power-supplying coils111, 112, and 113 to function as a power supplying resonator; and anoutput target switching mechanism which is configured to output avariable current to one of output targets which are at least one of andnot all of the power-supplying coils 111, 112, and 113 and to be capableof switching the output target to which the variable current is output.The output target switching mechanism of the oscillation controller 131is preferably arranged to repeatedly change a magnetic field state whichis a combination of the direction, density, and magnitude of magneticlines of force in a variable magnetic field. In this case, the magneticfield strength of the variable magnetic field in the predeterminedregion A is uniformized by repeatedly changing the magnetic field statewhich is a combination of the shape and density of magnetic lines offorce in the variable magnetic field. With this arrangement, when, forexample, the magnetic field formation device 101 is mounted on apower-supplying device, the power supply is possible without significantdeterioration in the power receiving efficiency depending on thedirection and position of the power-receiving device.

To be more specific, the oscillation controller 131 includes theoscillator 1312 configured to output a variable current and thepower-supplying coil short-circuit mechanism 1313 which is capable ofcausing the end portions 141 a and 142 a of the first current path 141and the second current path 142 of at least one of the power-supplyingcoils 111 and 112 to be short-circuited with each other. Thepower-supplying coil short-circuit mechanism 1313 is arranged to cause avariable current of the oscillator 1312 to flow in the power-supplyingcoils 111, 112, and 113 and stops the supply of the variable current tothe power-supplying coil 111, 112, or 113 at the same time as that coilis short-circuited. The power-supplying coil short-circuit mechanism1313 therefore has a function of switching the short-circuit of thepower-supplying coils 111, 112, and 113 and a function as a current pathswitcher (output target switching mechanism) of switching the outputtarget of the variable current of the oscillator 1312.

The magnetic field formation device 101 structured as above is able tocause at least one of the power-supplying coils 111, 112, and 113 tofunction as a power supplying resonator and change the distribution ofthe magnetic field strength of a variable magnetic field by sending amagnetic field to the power supplying resonator at a different angle.Furthermore, as the switching is repeated, a variable magnetic fieldwith magnetic field strength which is uniformized in a variation amountcan be formed at the predetermined region A. Furthermore, as at leastone of the power-supplying coils 111, 112, and 113 functioning as apower supplying resonator resonates, the magnetic field strength of thevariable magnetic field at the predetermined region A is enhanced.

(Magnetic Field Formation Device: Oscillation Controller: Oscillator)

The oscillator 1312 is configured to receive a current outputted fromthe power source PS and is capable to outputting a variable current withany oscillating frequency. The oscillating frequency of the oscillator1312 is preferably changeable to allow for the use of various types ofmagnetic field formation devices 101. Furthermore, each of theoscillating frequency, the voltage, and the current of the oscillator1312 may be changeable in accordance with the specification of thepower-supplying coil 111, 112, or 113 which is the output target.

While in the present embodiment the oscillator 1312 is indirectlyshort-circuited with the power-supplying coils 111, 112, and 113 via thepower-supplying coil short-circuit mechanism 1313, the disclosure is notlimited to this arrangement and the oscillator 1312 may be directlyshort-circuited to the power-supplying coils 111, 112, and 113. In thiscase, the variable current from the oscillator 1312 can be supplied toall power-supplying coils 111, 112, and 113. Alternatively, thepower-supplying coil short-circuit mechanism 1313 may be connected tothe power source PS and the oscillator 1312 may be provided on each ofcurrent paths connecting the power-supplying coil short-circuitmechanism 1313 with the respective power-supplying coils 111, 112, and113. In this case, the power-supplying coil short-circuit mechanism 1313is able to switch the power-supplying coil which is the output target ofthe variable current, by switching the output target of the currentoutput from the power source PS between the three oscillators 1312 onthe respective current paths.

(Magnetic Field Formation Device: Oscillation Controller:Power-Supplying Coil Short-Circuit Mechanism)

As shown in FIG. 12, the power-supplying coil short-circuit mechanism1313 includes: a switch mechanism which is configured to switchablyoutput a variable current from the oscillator 1312 to each of thepower-supplying coils 111, 112, and 113; and a short-circuit mechanismwhich is able to cause the end portions 141 a and 142 a of the firstcurrent path 141 and the second current path 142 of each of thepower-supplying coils 111, 112, and 113 to short-circuit with eachother.

The switch mechanism includes plural switches. Each of these switches isswitchable between connection (on-state) and disconnection (off-state)of an input end and an output end. The input ends of all switches areconnected to the oscillator 1312. Meanwhile, each output end isconnectable to one of the end portions 141 a and 142 a of the firstcurrent path 141 and the second current path 142 of the power-supplyingcoils 111, 112, and 113 via a switch of the short-circuit mechanism.With this arrangement, the switch mechanism supplies a variable currentfrom the oscillator 1312 to only one of the power-supplying coils 111,112, and 113, which is connected to a switch in the on-state.

The short-circuit mechanism includes switches which correspond to therespective power-supplying coils 111, 112, and 113. Each of theseswitches is able to switch between short-circuit (on-state) anddisconnection (off-state) between a first terminal and a secondterminal. The first terminal of each switch is connected to the endportion 141 a of the first current path 141 of each of thepower-supplying coils 111, 112, and 113. The second terminal of eachswitch is connected to the end portion 142 a of the second current path142 of each of the power-supplying coils 111, 112, and 113. With thisarrangement, the switches of the short-circuit mechanism are able tocause the end portions 141 a and 142 a of the first current path 141 andthe second current path 142 of each of the power-supplying coils 111,112, and 113 to be short-circuited or disconnected, by switching thefirst terminal and the second terminal between short-circuited(on-state) and disconnected (off-state). While in the present embodimentthe end portions 141 a and 142 a of the first current path 141 and thesecond current path 142 are short-circuited by the short-circuitmechanism, the disclosure is not limited to this arrangement. The endportions 141 a and 142 a maybe connected to the GND to beshort-circuited.

The switches of the above-described short-circuit mechanism are arrangedto operate in sync with the switch mechanism. To be more specific, theswitch mechanism stops the output of a variable current from theoscillator 1312 to the power-supplying coils 111, 112, and 113 for whichthe end portions 141 a and 142 a of the first current path 141 and thesecond current path 142 are short-circuited by a switch of theshort-circuit mechanism, whereas the switch mechanism outputs thevariable current from the oscillator 1312 to the power-supplying coils111, 112, and 113 for which the end portions 141 a and 142 a of thefirst current path 141 and the second current path 142 are disconnected.

The power-supplying coil short-circuit mechanism 1313 includes ashort-circuit control mechanism. The short-circuit control mechanism isable to switch each switch between the on-state and the off-state. Forexample, there are: a short-circuit pattern 1 in which the end portions141 a and 142 a of the first current path 141 and the second currentpath 142 of the power-supplying coil 111 are short-circuited; ashort-circuit pattern 2 in which the end portions 141 a and 142 a of thepower-supplying coil 112 are short-circuited; a short-circuit pattern 3in which the end portions 141 a and 142 a of the power-supplying coil113 are short-circuited; a short-circuit pattern 4 in which the endportions 141 a and 142 a of the power-supplying coils 111 and 112 areshort-circuited; a short-circuit pattern 5 in which the end portions 141a and 142 a of the power-supplying coils 112 and 113 areshort-circuited; and a short-circuit pattern 6 in which the end portions141 a and 142 a of the power-supplying coils 111 and 113 areshort-circuited. The short-circuit control mechanism is able to switch acombination selected from these short-circuit patterns 1 to 6 at anytiming. As described above, in the present embodiment, there are sixoutput targets as an output target of the variable current from theoscillator 1312, and the output target of the variable current isswitchable by the short-circuit control mechanism.

In addition to the above, the short-circuit control mechanism of thepower-supplying coil short-circuit mechanism 1313 has a function ofexecuting a process of short-circuiting the end portions 141 a and 142 awith a predetermined combination of a timing and a duration. With thisarrangement, the short-circuit control mechanism is able to easilygenerate a variable magnetic field with predetermined magnetic fieldstrength in consideration of heat generation and power consumption, byadjusting the timing and duration of the connection process.

To be more specific, the short-circuit control mechanism is able toselect one of plural short-circuit times (time 1 to time n), and asuitable short-circuit time is selected in consideration of the use andstate of the magnetic field formation device 101. The short-circuitcontrol mechanism is able to determine a timing to execute theshort-circuit operation between the end portions 141 a and 142 a, bymeans of plural short-circuit patterns. To be more specific, there are“every 1 pattern” with which the short-circuit operation is executedeach time one of the short-circuit patterns 1 to 6 is completed, “every2 patterns” with which the short-circuit operation is executed each timetwo of the short-circuit patterns 1 to 6 are completed, and so on. Asone of these options is selected, various short-circuit operations areexecutable at a desired timing.

(Magnetic Field Formation Device: Modification of OscillationController: Power-Supplying Coil Short-Circuit Mechanism and CurrentPath Switcher)

While in the oscillation controller 131 above the power-supplying coilshort-circuit mechanism 1313 executes a part of the function of thecurrent path switcher, the disclosure is not limited to thisarrangement. As shown in FIG. 13, a power-supplying coil short-circuitmechanism 1313A and a current path switcher 1311 may be independentlyprovided. Control is easily done in this case, because control forshort-circuiting is separated from control for current switching.

To be more specific, the oscillation controller 131 includes thepower-supplying coil short-circuit mechanism 1313A including only theshort-circuit mechanism, the oscillator 1312, and the current pathswitcher 1311 which performs switching to supply the variable current ofthe oscillator 1312 to at least one of and not all of thepower-supplying coils 111, 112, and 113.

(Magnetic Field Formation Device: Oscillation Controller: Current PathSwitcher)

The current path switcher 1311 includes a switch mechanism which isconfigured to switchably output the variable current of the oscillator1312 to each of the power-supplying coils 111, 112, and 113. The switchmechanism includes plural switches. Each of these switches is switchablebetween connection (on-state) and disconnection (off-state) of an inputend and an output end. The input ends of all switches are connected tothe oscillator 1312. Meanwhile, the output ends are connected to therespective power-supplying coils 111, 112, and 113. With thisarrangement, the switch mechanism supplies a variable current from theoscillator 1312 to only one of the power-supplying coils 111, 112, and113, which is connected to a switch in the on-state.

As shown in FIG. 14, the current path switcher 1311 includes a switchcontrol mechanism. The switch control mechanism is able to switch eachswitch of the switch mechanism between the on-state and the off-state.For example, provided that a route through which the variable current issupplied to the power-supplying coil 111 is a route A, a route throughwhich the variable current is supplied to the power-supplying coil 112is a route B, and a route through which the variable current is suppliedto the power-supplying coil 113 is a route C, there are six connectionpatterns 1 to 6.

To be more specific, there are (1) a connection pattern 1 with which thevariable current is supplied only to the power-supplying coil 111 byusing only the route A; (2) a connection pattern 2 with which thevariable current is supplied only to the power-supplying coil 112 byusing only the route B; (3) a connection pattern 3 with which thevariable current is supplied only to the power-supplying coil 113 byusing only the route C; (4) a connection pattern 4 with which thevariable current is supplied to the power-supplying coils 111 and 112 byusing the route A and the route B; (5) a connection pattern 5 with whichthe variable current is supplied to the power-supplying coils 112 and113 by using the route B and the route C; and (6) a connection pattern 6with which the variable current is supplied to the power-supplying coils111 and 113 by using the route A and the route C. The switch controlmechanism is able to switch a combination selected from these connectionpatterns 1 to 6 at any timing.

In addition to the above, the switch control mechanism of the currentpath switcher 1311 has a function of executing a stop process of notsupplying the variable current to any of the power-supplying coils 111,112, and 113, with a predetermined combination of a timing and aduration. With this arrangement, the switch control mechanism is able toeasily generate a variable magnetic field with predetermined magneticfield strength in consideration of heat generation and powerconsumption, by adjusting the timing and duration of the stop process.

To be more specific, the switch control mechanism is able to perform apause operation (stop process) of stopping the power supply to all ofthe power-supplying coils 111, 112, and 113 by turning off all switchesof the switch mechanism. In the pause operation, a pause time isselectable from plural pause times (time 1 to time n), and a suitablepause time is selected in consideration of the use and state of themagnetic field formation device 101.

In addition to the above, the switch control mechanism is able todetermine a timing to execute the pause operation based on plural pausepatterns. To be more specific, there are “every 1 pattern” with whichthe pause operation is executed each time one of the connection patterns1 to 6 is completed, “every 2 patterns” with which the pause operationis executed each time two of the connection patterns 1 to 6 arecompleted, and so on. As one of these options is selected, various pauseoperations are executable at a desired timing.

For example, the current path switcher 1311 is able to perform apowering operation in which a route A connection state with theconnection pattern 1, the pause operation, a route B connection statewith the connection pattern 2, the pause operation, a route C connectionstate with the connection pattern 3, and the pause operation arerepeated in order. Furthermore, for example, the current path switcher1311 is able to perform a powering operation in which the route Aconnection state with the connection pattern 1, the route B connectionstate with the connection pattern 2, the route C connection state withthe connection pattern 3, and the pause operation are repeated in order.

The current path switcher 1311 may be constituted by a circuit having aprogrammability such as a microcomputer and an operation of switchingthe variable current may executed by software, or may be constituted bya combination of ICs and the switching operation may be executed byhardware.

(Application Example of Magnetic Field Formation Device)

The following will describe a case where the magnetic field formationdevice 101 structured as above is used in a power-supplying device asshown in FIG. 15. To put it differently, the following will describe acase where the magnetic field formation device 101 is mounted on thecharger 7 as a power-supplying device and electric power is supplied ina wireless manner to the power-receiving module 9 which is apower-receiving device of the driving device 5 provided in the charger7.

The charger 7 (power-supplying device) on which the magnetic fieldformation device 101 is mounted and the driving device 5 (secondarybattery 10, power-receiving module 9) constitute a powerreceiving/supplying device 1 or a power receiving/supplying system. Toput it differently, the power receiving/supplying device 1 includes thedriving device 5 including the power-receiving coil mechanism 2receiving power by a magnetic field and the charger 7 supplying power tothe driving device 5 by wireless transmission.

In the power receiving/supplying device 1, the charger 7 and the drivingdevice 5 may be treated in combination. While the description belowdeals with a case where the power-receiving coil mechanism 2 receivespower by magnetic field resonance, the disclosure is not limited to thisarrangement and it may receive power by electromagnetic induction.

(Application Example of Magnetic Field Formation Device: Charger andHousing Cup)

The charger 7 includes the housing cup 6 in which the driving device 5such as a mobile device including a power-receiving device is mountedand the magnetic field formation device 101 which is configured togenerate a variable magnetic field at the housing region B of thehousing cup 6 to allow the power-receiving module 9 to receive powerirrespective of the direction and position of the power-receiving module9. The housing cup 6 maybe arranged such that plural driving devices 5are simultaneously placed at the housing region B. To put itdifferently, the housing region B of the housing cup 6 may have acapacity capable of simultaneously storing plural driving devices 5.

The magnetic field formation device 101 is provided in a casing of thecharging case 60 in which the housing cup 6 is provided. When themagnetic field formation device 101 is employed in the charger 7, any ofthe power-supplying coils 111, 112, and 113 functions as a power feedingcoil 31 whereas the remaining power-supplying coils 111, 112, and 113function as a power-supplying resonator. A power-supplying coilmechanism 3 including the power feeding coil 31 is connected to anoscillation control circuit 81 which is an IC chip in which theoscillation controller 131 outputting a variable current is embodied.

The oscillation control circuit 81 and the power-supplying coilmechanism 3 are combined as a power-supplying module 8 in order toimprove the handleability. The oscillation control circuit 81 isconnected to a USB terminal 61. The USB terminal 61 is connectable to anunillustrated USB cable of an external device such as a personalcomputer provided outside the charger 7, so that 5V DC power can besupplied from the external device to the oscillation control circuit 81.Instead of the USB terminal 61, the charger 7 may be connected to a homeAC power cord, and DC power converted from AC power by a rectifyingcircuit or a converter may be suppliable to the oscillation controlcircuit 81.

(Application Example of Magnetic Field Formation Device: Driving Device)

An example of the driving device 5 charged and driven by theabove-described charger 7 is a mobile device. The mobile deviceencompasses a handheld device which can be carried on a hand and ahuman-wearable device which can be worn a human body. Specific examplesof the mobile device include a portable computer (a laptop PC, a notePC, a tablet PC, or the like), a headset, a camera, an audio visualdevice (a portable music player, an IC recorder, a portable DVD player,or the like), a calculator (such as a pocket computer and an electroniccalculator), a game console, a computer peripheral (a portable printer,a portable scanner, a portable modem, or the like), a dedicatedinformation device (an electronic dictionary, an electronic notebook, anelectronic book, a portable data terminal, or the like), a portablecommunication terminal, a voice communication terminal (a portablephone, a PHS, a satellite phone, a third party radio system, an amateurradio, a specified low power radio, a personal radio, a citizen radio,or the like), a data communication terminal (a portable phone, a PHS (afeature phone and a smart phone), a pager, or the like), a broadcastingreceiver (a television receiver and a radio), a portable radio, aportable television receiver, a one-seg receiver, another type of device(a wristwatch and a pocket watch), a hearing aid, a handheld GPS, asecurity buzzer, a flashlight/pen light, a battery pack, and the like.Examples of the above hearing aid include an ear-hook hearing aid, anear hole fitting hearing aid, and a glasses-type hearing aid. Thedriving device 5 maybe a desktop device such as a personal computer.

(Application Example of Magnetic Field Formation Device: Driving Device:Power-Receiving Coil Mechanism)

The driving device 5 includes the power-receiving coil mechanism 2 whichis configured to receive power by a magnetic field. In addition to thepower-receiving coil mechanism 2, the driving device 5 includes: a powercontrol circuit 91 to which power is supplied from the power-receivingcoil mechanism 2; and a magnetic member 4. The power-receiving coilmechanism 2, the power control circuit 91, and the magnetic member 4 areintegrated as a power-receiving module 9. The power-receiving module 9is connected to a secondary battery 10.

The power-receiving coil mechanism 2 is configured to receive power insuch a way that magnetic field resonance is caused by a variablemagnetic field in the housing region B (predetermined region A). To bemore specific, the power-receiving coil mechanism 2 includes apower-receiving coil 21 and a power-receiving resonator 22 provided onthe inner circumferential side of the power-receiving coil 21. The“magnetic field resonance” indicates a resonance phenomenon ofsynchronization at a resonance frequency of a variable magnetic field.Examples of the types of coils used in the power-receiving coil 21 andthe power-receiving resonator 22 include: a spiral type, a solenoidtype, and a loop type. In regard to the positional relation between thepower-receiving coil 21 and the power-receiving resonator 22, thepower-receiving coil 21 may be provided on the inner circumferentialside or the outer circumference side of the power-receiving resonator22, or the power-receiving coil 21 and the power-receiving resonator 22may be provided not to overlap each other in the radial direction.

The driving device 5 includes the magnetic member 4 provided at thepower-receiving coil mechanism 2. The magnetic member 4 increases themagnetic field strength by increasing the mutual inductance of thepower-receiving coil mechanism 2 and increasing the magnetic fluxdensity. As the magnetic field strength of the power-receiving coilmechanism 2 is increased by the magnetic member 4, the chargingcharacteristic is maintained to be high in the power-receiving coilmechanism 2, and power at least at a desired level is receivable with animproved degree of freedom in the layout of the power-receiving coilmechanism 2. The power-receiving coil mechanism 2 preferably includesthe magnetic member 4 but may not include the magnetic member 4.

The magnetic member 4 is provided on the inner circumferential side ofthe power-receiving coil mechanism 2. While the positional relationbetween the power-receiving coil mechanism 2 and the magnetic member 4in the axial direction, i.e., the positional relation when viewed in thedirection orthogonal to the axial direction is not particularly limited,these members are preferably provided so that the power-receiving coilmechanism 2 is provided at an intermediate portion between one end sideand the other end side of the magnetic member 4. This “intermediateportion” between one end side and the other end side of the magneticmember 4 indicates a part of a region sandwiched between the one end andthe other end, excluding the one end and the other end.

The positional relation between the power-receiving coil mechanism 2 andthe magnetic member 4 in the axial direction is further preferablyarranged so that the power-receiving coil mechanism 2 is provided at acentral portion between one end side and the other end side of themagnetic member 4. The positional relation between the power-receivingcoil mechanism 2 and the magnetic member 4 in the axial direction ispreferably arranged such that the charging characteristic of themagnetic member 4 is not significantly different between a case wherethe coil surface 2 a of the power-receiving coil mechanism 2 on one sidefaces a magnetic field generating surface 3 a of the power-supplyingcoil mechanism 3 and a case where the coil surface 2 b of thepower-receiving coil mechanism 2 on the other side faces the magneticfield generating surface 3 a.

The power-receiving resonator 22 of the power-receiving coil mechanism 2is provided so that the power-receiving coil 21 is disposed on the outercircumference side. To be more specific, the power-receiving coilmechanism 2 is arranged such that the power-receiving resonator 22 isprovided between the power-receiving coil 21 on the outermostcircumferential side and the magnetic member 4 on the innermostcircumferential side. While the positional relation between thepower-receiving resonator 22 and the power-receiving coil 21 in theaxial direction is not particularly limited, these members arepreferably provided so that the power-receiving coil 21 is provided atan intermediate portion between one end side and the other end side ofthe power-receiving resonator 22. The positional relation between thepower-receiving resonator 22 and the power-receiving coil 21 in theaxial direction is further preferably arranged so that thepower-receiving coil 21 is provided at a central portion between one endside and the other end side of the power-receiving resonator 22.

The magnetic member 4 is made of resin in which magnetic powder isdispersed. The resin used for the magnetic member 4 may be thermosettingresin or thermoplastic resin, and is not particularly limited. Examplesof the thermosetting resin include epoxy resin, phenol resin, melamineresin, vinyl ester resin, cyano ester resin, maleimide resin, andsilicon resin. Examples of the thermoplastic resin include acrylicresin, vinyl acetate based resin, and poly vinyl alcohol based resin.The present example adopts a resin whose main component is epoxy resin.

Further, soft magnetic powder is used as the magnetic powder dispersedin the resin. Examples of the soft magnetic powder include pure Fe,Fe—Si, Fe—Al—Si (sendust), Fe—Ni (permalloy), soft ferrites, Fe-baseamorphous, Co-base amorphous, and Fe—Co (permendur); however, is notparticularly limited. The shape of the magnetic member 4 is suitablydetermined, too.

(Application Example of Power Receiving/Supplying Device 1: DrivingDevice: Power Control Circuit)

The power control circuit 91 is mounted on a circuit substrate.

As shown in FIG. 16, the power control circuit 91 has a function ofcontrolling the charging of the secondary battery 10. The power controlcircuit 91 may be a circuit further having a function of controlling thedischarging.

To be more specific, the power control circuit 91 includes arectification stabilization unit 911 which is configured to output DCpower by rectifying AC power supplied from the outside via thepower-receiving coil mechanism 2 outputting the DC power, a chargingunit 912 configured to supply the DC power outputted from therectification stabilization unit 911 to the secondary battery 10 at acharging voltage, and a transformation unit 913 configured to execute asignal process. The transformation unit 913 is connected to a drivingmechanism 11 which is driven by the charged power of the secondarybattery 10.

The rectification stabilization unit 911 is arectification-stabilization IC, for example. Therectification-stabilization IC is an IC in which functions such as fullbridge synchronous rectification, voltage conditioning and wirelesspower control, and protection from a voltage, current, or temperatureanomaly are integrated into one chip. The rectification stabilizationunit 911 may not be provided when the power outputted from thepower-receiving coil mechanism 2 is DC power.

The charging unit 912 is an IC (charging circuit) for a constantcurrent/constant voltage linear charger, and has functions such as afunction of notifying that the charging current has been reduced to apredetermined setting value, a function of ending the charging using atimer, a function of stabilizing the charging current by means ofthermal feedback, and a function of limiting the chip temperature in ahigh-power mode or in high ambient temperatures.

The transformation unit 913 is a transformer circuit which functions asa transformation unit performing signal processing of converting thecharged power of the secondary battery 10 to the driving power for thedriving mechanism 11 and outputting the converted power. As thetransformation unit 913, a linear regulator may be employed for voltagedropping, or a switching regulator or a charge pump may be employed forvoltage boosting and voltage dropping. An example of each regulator isone adopting a semiconductor elements so the current is switched on andoff at a high speed.

(Application Example of Power Receiving/Supplying Device 1: DrivingDevice: Power Control Circuit with High-Capacitance Capacitor)

As shown in FIG. 17 and FIG. 18, the power control circuit 91 mayinclude a high-capacitance capacitor as a first-stage power storage unit920. The first-stage power storage unit 920 has a capacity ofdischarging at a voltage equal to or higher than the minimum operatingvoltage of an electric part on a subsequent stage, and is preferablyprovided in cases where a received voltage varies. The “electric part”encompasses not only a secondary battery and an electronic circuitsubstrate but also all driving devices driven by supplied power. The“minimum operating voltage” indicates the minimum voltage with which anelectric part is properly driven. For example, the minimum operatingvoltage of a secondary battery is the minimum voltage with which acharging IC of the secondary battery is properly driven.

The first-stage power storage unit 920 is particularly preferable whenswitching of conduction to the power feeding coil 31 is performed by thepower-supplying coil short-circuit mechanism 1313 or the current pathswitcher 1311. To be more specific, the driving device 5(power-receiving device) including the power control circuit 91 may beconfigured to receive power by a variable magnetic field generated atthe predetermined region A by the magnetic field formation device 101,and may include: the power-receiving coil mechanism 2 (power-receivingmechanism) configured to receive power by the variable magnetic field;and the first-stage power storage unit 920 (high-capacitance capacitor)having a capacity of being charged by a current received by thepower-receiving coil mechanism 2 and discharging at least at the minimumoperating voltage of the secondary battery 10, etc. (electric part) on asubsequent stage while the current path switcher 1311 is performing theswitching of the output target.

The driving device 5 may include: the power-receiving coil mechanism 2(power-receiving device) configured to receive power by a variablemagnetic field; and a capacitor having a capacity of being charged by acurrent received by the power-receiving coil mechanism 2 and dischargingat least at the minimum operating voltage of the secondary battery 10,etc. (electric part) on a subsequent stage while the current pathswitcher 1311 is performing the stop process.

According to the arrangement above, even when an induced current cannotbe obtained from the power-receiving coil mechanism 2 on account of theswitching process or the stop process performed for the power feedingcoil 31, the charging unit 912 or the like is stably driven because thefirst-stage power storage unit 920 performs the discharge at least atthe minimum operating voltage of the charging unit 912 or the like.

The first-stage power storage unit 920 (high-capacitance capacitor) mayhave a capacity of discharging at least at the minimum operating voltageof an electric part on a subsequent stage during the stop process inwhich the current path switcher 1311 does not supply a variable currentto the power feeding coil 31 (power-supplying coil), in addition to theperiod during which the switching of the output target is beingperformed by the power-supplying coil short-circuit mechanism 1313 orthe current path switcher 1311. According to this arrangement, inaddition to the period during which the switching of the output targetis being performed by the current path switcher 1311, even when aninduced current cannot be obtained from a power-receiving coil due tothe stop process for the power-supplying coil and the power supplyingresonator, the electric part is stably driven as the first-stage powerstorage unit 920 performs the discharge at least at the minimumoperating voltage of the electric part.

(Application Example of Power Receiving/Supplying Device: DrivingMechanism: Driving Device)

Examples of the driving mechanism 11 include a mechanism in which acomponent converting electric power to kinetic energy such as a speakerand a motor is incorporated, a light emitting mechanism or anillumination mechanism in which a component converting electric power tooptical energy such as an LED light source and a laser light source isincorporated, and a microcomputer. Apart from these mechanisms, anytypes of mechanism driven by electric power may be used as the drivingmechanism 11. The power-receiving coil mechanism 2 is configured tocorrespond to wireless power supply with which power supply is carriedout in a mechanically contactless state. Examples of the wireless powersupply include electromagnetic induction and magnetic field resonance(magnetic resonance).

(Application Example of Power Receiving/Supplying Device: DrivingDevice: Secondary Battery)

As the secondary battery 10, any type of batteries which are chargeableand rechargeable can be used. Examples of the secondary battery 10include a lead storage battery, a valve-regulated lead storage battery,a lithium ion battery, a lithium ion polymer battery, a lithium ironphosphate ion battery, a lithium-sulfur battery, a lithium titanatebattery, a nickel-cadmium storage battery, a nickel-hydrogenrechargeable battery, a nickel-iron battery, a nickel-lithium battery, anickel-zinc battery, a rechargeable alkali battery, a sodium-sulfurbattery, a redox flow battery, a zinc-bromine flow battery, a siliconbattery, and a Silver-Zinc battery.

Although the above descriptions have been provided with regard to thecharacteristic parts so as to understand the invention more easily, theinvention is not limited to the embodiment as described above and can beapplied to the other embodiments and the applicable scope should beconstrued as broadly as possible. Furthermore, the terms and phraseologyused in the specification have been used to correctly illustrate thepresent invention, not to limit it. In addition, it will be understoodby those skilled in the art that the other structures, systems, methodsand the like included in the spirit of the present invention can beeasily derived from the spirit of the invention described in thespecification. Accordingly, it should be considered that the presentinvention covers equivalent structures thereof without departing fromthe spirit and scope of the invention as defined in the followingclaims. In addition, it is required to sufficiently refer to thedocuments that have been already disclosed, so as to fully understandthe objects and effects of the present invention.

REFERENCE SIGNS LIST

1 power receiving/supplying device

2 power-receiving coil mechanism

3 power-supplying coil mechanism

4 magnetic member

5 driving device

6 housing cup

7 charger

8 power-supplying module

9 power-receiving module

10 secondary battery

21 power-receiving coil

22 power-receiving resonator

31 power feeding coil

111 power-supplying coil

112 power-supplying coil

131 oscillation controller

1111 power supplying sub coil

1112 power supplying sub coil

1311 current path switcher

1312 oscillator

A predetermined region

B housing region

1. A magnetic field formation device comprising: power-supplying coilseach of which generates a variable magnetic field by receiving avariable current via a first current path on one coil end side and asecond current path on the other coil end side; a resonance capacitorwhich is provided on at least one of the first current path and thesecond current path; and a power-supplying coil short-circuit mechanismwhich is capable of causing at least one of the power-supplying coils tofunction as a power supplying resonator by short-circuiting end portionsof the first current path and the second current path.
 2. The magneticfield formation device according to claim 1, which is configured togenerate a variable magnetic field at a predetermined region, wherein,all of the power-supplying coils are disposed so that coil surfacesoppose the predetermined region, and at least one of the power-supplyingcoils is disposed to have a coil surface direction which intersects withcoil surface directions of the other power-supplying coils.
 3. Themagnetic field formation device according to claim 1, which isconfigured to generate a variable magnetic field at a predeterminedregion, wherein, all of the power-supplying coils are disposed so thatcoil surfaces oppose the predetermined region, and at least one of thepower-supplying coils is disposed to have a coil surface direction whichis parallel to coil surface directions of the other power-supplyingcoils.
 4. The magnetic field formation device according to claim 1,further comprising a current output controller which is configured tooutput a variable current to one of output targets which are at leastone of and not all of the power-supplying coils and to be capable ofswitching the output target to which the variable current is output. 5.The magnetic field formation device according to claim 1, wherein, thecurrent output controller executes a stop process of not outputting thevariable current to any of the power-supplying coils, with apredetermined combination of a timing and a duration.
 6. Apower-supplying device comprising the magnetic field formation deviceaccording to claim
 1. 7. A power-receiving device comprising apower-receiving mechanism which is configured to receive power by avariable magnetic field generated at a predetermined region by themagnetic field formation device according to claim
 1. 8. Apower-receiving device configured to receive power by a variablemagnetic field generated at a predetermined region by the magnetic fieldformation device according to claim 3, comprising: a power-receivingmechanism configured to receive power by the variable magnetic field;and a high-capacitance capacitor which has a capacity of being chargedby a current received by the power-receiving mechanism and dischargingat least at a minimum operating voltage of an electric part on asubsequent stage while an output target of the variable current by thecurrent output controller is being switched.
 9. The power-receivingdevice according to claim 8, wherein, the high-capacitance capacitor hasa capacity of discharging at least at the minimum operating voltage ofthe electric part on the subsequent stage during a stop process in whichthe current output controller does not supply the variable current toany of the power-supplying coil.
 10. A power receiving/supplying devicecomprising: a power-supplying device including the magnetic fieldformation device according to claim 1; and a power-receiving deviceincluding a power-receiving mechanism which is configured to receivepower by the variable magnetic field generated by the power-supplyingdevice.
 11. A mobile device comprising a power-receiving mechanism whichis configured to receive power by a variable magnetic field generated ata predetermined region by the magnetic field formation device accordingto claim
 1. 12. A coil device comprising a coil; a variable currentsupplying mechanism configured to supply a variable current to the coilvia a first current path on one coil end side and a second current pathon the other coil end side; a resonance capacitor which is provided onat least one of the first current path and the second current path; anda coil short-circuit mechanism which is capable of forming a powersupplying resonator by short-circuiting end portions of the firstcurrent path and the second current path.
 13. A magnetic field formationmethod comprising the steps of: generating a variable magnetic field bysupplying a variable current via a first current path on one coil endside and a second current path on the other coil end side; and switchingat least one of power-supplying coils to a power supplying resonator byshort-circuiting end portions of the first current path and the secondcurrent path, a resonance capacitor being provided on at least one ofthe first current path and the second current path of thepower-supplying coils.